With the rapid development of industry, air is deteriorating more and more and people concern air quality grades such as PM2.5 more and more. In order to avoid inhaling polluted air as much as possible, many users have installed air purifiers at homes. However, the drawback with an air purifier is that the air purifier can not purify indoor air in a short time, and therefore the householders are inhaling non-purified air continuously as well while purifying the air. In addition, using an air purifier while windows are closed for a long time makes indoor air incapable of circulating with outdoor air, leading to increase of concentration of indoor carbon dioxide, which can not guarantee people's health too.